One of the biggest problems that a building construction contractor or worker faces is an "in-the-air" task (i.e., a task that must be done above the height of an ordinary worker, usually at or above the ceiling height). "In-the-air" tasks include, for example, the installation or rearrangement of plumbing piping, air-conditioning ducts, fire sprinkler piping, electrical lighting fixtures, and acoustical ceiling tile. The performance of such tasks can require the use of specialized hand-held tools, for example, to drill into the ceiling slab to insert hangers, to cut a portion of piping or to affix sections of duct together by screw or otherwise. The usual method to overcome the obstacle of height is to raise the level of the worker, for example, by using a ladder, or in certain situations, constructing a scaffold. A ladder is normally used when a single worker can complete a task; a scaffold is usually used when large areas are under construction or renovation or when several workers need to be above the ground to perform a task or tasks. The ladder and the scaffold each perform the function of providing a temporary platform for a worker to sit or stand on when working above the ground level.
However, both ladders and scaffolding have limitations and drawbacks in providing such a platform. As mentioned above, a ladder is restricted to one area and can hold only one worker at a time. Second, even the best-equipped worker cannot compensate for the lost time of travelling up and down a ladder, for example, to retrieve supplies, to move the ladder to another location or position, or to broadly inspect the work just completed. Such lost time translates into additional expense for the contractor and the contractee. Third, construction labor union contracts usually specify that additional manpower is required to hold a ladder in place while a worker is using it, thereby driving up the cost of utilizing a ladder even for the simplest of tasks. Fourth, it is cumbersome and, more importantly, hazardous to work with hand-held tools on a ladder because of the limited stability of a ladder.
Scaffolding overcomes only some of the limitations of a ladder, by providing a larger platform area for more than one worker and by providing greater stability when working with certain hand-held tools. However, certain other hand-held tools, such as drills, generate a great amount of torque or force and thus can create a certain degree of instability even when a worker using such a tool is stationed on the ground. Second, positioning a scaffold is more cumbersome than positioning a ladder so that certain ceiling areas cannot be reached without consuming time and, at times, without resorting to a ladder or other means of support. Third, scaffolding is expensive and time-consuming to construct and to dissemble. Fourth, both a scaffold and a ladder raise the level of a worker to the elevated work zone. Disadvantageously, however, this may not be desired if the operation of the tool causes dust, metal fragmentation and the like, or the work zone is inherently hazardous, such as asbestos-lined ceilings. Thus, neither device can shield a worker who is already in a vulnerable position by being off the ground.